Are you saying that because something is digital and exists as data on a computer, that it is not valid? As opposed to something on paper? How is that different in any real way? Paper is transitory -- anyone can forge a signature or reprint a contract and photocopy your name on it and shred the original and put the modified one in the file cabinet. Just because the materials used are different doesn't make the law any less applicable.
This is an actual issue in consumer banking. If a bank forges a paper document, it's possible to hold up the original countercopy (assuming you filed it) and say "No, your document is fake, and you are attempting fraud."
These agreements often have millions of copies, so it's easy to find the applicable version of the T&Cs.
If all you have are digital T&Cs at the end of a web link, and those T&Cs can be updated at any time, and you are only ever sent the link, and not the updated T&Cs - you have nothing.
You could argue that everyone should download every T&C update. In theory that's true. But in practice a problem that could be solved relatively simply - keep a single letter - now requires many more steps, backup strategies, and so on.
You could also argue that banks should keep copies of their T&C versions and supply them on request. Which they do - except that in practice a bank that's trying to forge a document won't have a problem forging T&Cs.
This not hypothetical. I've known people win court cases because they kept a single piece of paper.
